Process for facilitating the penetration of latex into textile fibers, threads, tissues, cords, and other textile materials



' solution and the pH Patented Oct. 29, 1935 UNITED STATES.

2,019,420 PROCESS FOR FACILITATING THE PENE- TBATION OF vBEES, THREADS, TISSUES,

OTHER TEXTILE MATERIAL LATEX INTO TEXTILE FI- SORDS, AND

Lon Sylvain Max Lejeune, Wasquehal, and Jean Etienne Charles Bongrand, Paris, France No Drawing. Application October 28, 1932, Serial No. 640,126. In France March 7, 1932 9 Claims. (01. 91-68 This invention consists of improvements in or relating to processesrfor facilitating the penetration of latex into textile fibers, threads, tissues, cords and other textile materials.

In this specification the expression yams includes unspun or spun yarns and the expression fabrics" includes cords, tissues orother woven, knitted, braided or otherwise manufactured textiles. The symbol pH is used for hydrogen ion concentration.

When a textile material (fiber, yarn or fabric), not having been submitted to special treatment, is placed in a more or less concentrated solution of ordinary latex, it is noticeable that the latex penetrates with dimculty into the interior and has a tendency to coagulate superficially, and this is true of material containing few fibers or even of a simple fiber.

The explanation of this non-penetration of the ordinary latex into the interior of the unprepared textile fiber is as followsz-Ordinary latex as it is prepared with a view to storage and use is found in alkaline (generally ammoniacal) varies generally between 10 and 11.5. The majority of textile fibers, cotton, hemp, jute, sisal, etc. for example, occur in the raw state with an acid pH, which varies generally between 4.5 and 6. acid pH 'are brought in contact with latex having alkaline pH 9. chemical neutralizatioioccurs at the point of contact of the latex with the fiber and there follows partial coagulation of the rubber latex in the form of an almost invisible film, which, however, is sumcient to stop the further penetration of the latex into the fiber.

By using physical means, for example pressure, or more particularly the process described and claimed in U. S. patent specifications Serial Nos. 443,467 and 443,470, successful attempts have been made to cause latex to penetrate textile fibers. By means of the preparatory treatment forming the subject-matter of the present invention this penetration is secured in a more perfect er.

with this object the present invention consists in a process for facilitating the penetration of latex into textile materials (fibers, yarns or fabrics) while avoiding premature coagulation which process includes the step of adjusting the hydrogen ion concentration of the textile materials or of the latex or both.

The said adjustment consists, in the case of the pH of textile materials, in a preliminary treatment of the said textile materials in a cold or hot state, by alkaline solutions, with or without When these fibers with agitation of the said fibers or mixing of the alka line solutions, in a vacuum or under pressure, so that the pH of the said textile materials, which is acid, becomes alkaline, that is to say higher than 7, and may be substantially the same as that of ordinary latex or even higher.

The saidadjustment consists in the case of ordinary latex, which is alkaline, in rendering it acid, that is to say in causing it to take a pH lower than 7 before bringing it into contact with the textile fibers which themselves have an acid pH that is lower than 7. This latter adjustment is obtained by the addition to the latex of acid solutions, in presence of peptizers which avoid the flocculation of coagulation of the rubber in an acid medium and said acid solutions can themselves be peptizing solutions. The peptizers in question may for example be certain wettingagents notably those which are found in commerce under the trade names Hygrolite", Nekal", etc.; both these wetting agents being well known to persons skilled in the art and being fully identified to such by their said trade names Hygrolite is composed essentially of an aqueous solution of oil containing sulphur and formaldehyde and having a general analysis of 75 parts by weight of water,

7.5 parts by-weight of water, formaldehyde and trioxymethylene,

17.5 parts by weight of soapy materials.

Nekal" is a wetting agent which has both solvent and emulsifying properties and consists of a mixture of 40% sodium sulphate and 60% sodium butyl naphthylene sulphonate.

A double adjustment may also be utilized and consists in causing the textile fibers of a pH which is generally acid, to have an alkaline pH, 10 for example in the manner indicated above. and then at the'same time in treating the ordinary latex to bring it to an acid pH, 5 for example in the manner indicated above. The treated latex charged with peptizing materials which prevent the flocculation or coagulation of the rubber, is more viscous than ordinary alkaline latex, and in contact with the textile fiber with alkaline pH it fiuidifies, and, by a phenomenon oi osmosis it penetrates into said textile fiber.

Example-Raw cotton 01' pH 5 is boiled for three hours, with for example a 2 to 5% solution of carbonate of soda in known conditions such that the-fibers are not weakened. After, thistreatment the cotton has a pH higher than 7, and according to whether it is rinsed more or less the pH may vary between 7 and 11. The value 01' the pH is measured by the usual processes.

The cotton of alkaline pH may then be brought into contact with the ordinary alkaline latex.

The processes above described are preferably used in conjunction with the methods described and claimed in U. S. patent specifications Serial Nos. 443,467 and 443,470.

We claim:

1. In a process for the impregnation of textile material with rubber latex in a closed vessel under fluid pressure, the preliminary step of adjusting the relative hydrogen ion concentration of the latex and of the textile material to substantially the same value thereby avoiding coagulation of the latex at the interfaces of the latex and the textile material.

2. In a process for the impregnation of textile material with rubber latex in a closed vessel untier fluid pressure, the preliminary step of adjusting the hydrogen ion concentration of the latex and of the textile material. to substantially the same value thereby avoiding coagulation of the latex upon the interfaces of the latex and the textile material during impregnation.

3. In a process for the impregnation of textile material with rubber latex in a closed vessel under fluid pressure, the preliminary step of treating the textile material with an alkaline solution to bring its pH throughout to that of the latex in order to avoid coagulation of the latex at the interfaces of the latex and the textile material.

4. In a process for the impregnation of textile material with rubber latex in a closed vessel under fluid pressure, the preliminary step of treating the textile material with an aqueous solution of alkali accompanied by variation of the fluid pressure to bring the pH of the textile material to that of the latex in order to avoid coagulation of the latex at the interfaces of the latex and the textile material.

5. In a process for the impregnation of textile material with rubber latex in a closed vessel under fluid pressure, the preliminary step of treating the textile material with an aqueous alkaline solution to bring the pH of the textile material throughout to that of the latex is order to avoid premature coagulation of .the latex at the interfaces of the latex and the textile material.

6. In a process for the impregnation of textile material having an acid pH with rubber latex in a closed vessel under fluid pressure, the preliminary step of treating the textile flber with an aqueous alkaline solution to raise the pH to an alkaline value approximating and subsequent-.

ly bringing thesaid textile material into contact with an alkaline latex solution.

7. In a process for the impregnation of textile material having an acid pH with an alkaline rubber latex dispersion in a closed vessel under fluid pressure, the preliminary step of treating the textile material with an aqueous alkaline solution to raise the pH to an alkaline value approximating 10 in order to avoid premature coagulation of the latex at the interfaces of the latex and the textile material.

8. In a process for the impregnation of textile material having an acid pH with rubber latex having an alkaline pH in a closed vessel under fluid pressure, the preliminary steps of boiling the textile material with a dilute alkaline solution to bring its pH throughout to a value above that of the latex, and rinsing the textile material to bring its pH to that of the latex in order to avoid coagulation of the latex at the interfaces of the latex and the textile material duringthe subsequent impregnation.

9. In a process for the impregnation of cotton with an alkaline dispersion of rubber latex in a closed vessel under fluid pressure, the preliminary steps of boiling the cotton with a dilute solution of sodium carbonate to bring the pH of the cotton to a value above that of the latex and rinsing the cotton to reduce its pH to that of the latex.

LEON SYLVAIN MAX LEJEUNE. JEAN ETIENNE CHARLES BONGRAND. 

